Lewandowski will still have a year remaining on his contract at the end of the season. It means United, and other interested parties, face having to pay a premium transfer fee on top of his salary.
“I am open to everything. I’m quiet. It is important for me to be able to focus on my game, always on what can happen in the last match,” Lewandowski said at the start of March. “Everything that remains to be done regarding the contracts is a secondary issue and remains in the background.”
The Poland international has previously revealed he was close to joining United in 2012. He held talks with then-boss Sir Alex Ferguson but instead decided to remain at Borussia Dortmund.